Aurin dye.



UNITED STATES PATENT ()FFICE.

MAX WEILER, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBENFABRIKEN VORM. FRIEDR. BAYER & 00., OF ELBERFELD, GERMANY, A CORPORATION OF GERMANY.

Patented Dec. 13, 1910.

AURIN DYE,

978,799. Specification of Letters Patent.

No Drawing.

T 0 all whom it may concern:

Be it known that 1, MAX ainan, doctor of philosophy, chemist, citizen of the German Empire, residing at Elberfeld, Germany, have invented new and useful Improvements in a New Dye, of which the following is a specification.

My invention relates to the manufacture and production of new dyestuffs of the aurin series, which are obtained by condensing in the presence of oxidizing agents methylene oxyca-rboxylic acids, especially methylenedi salicylic acid and methylene di orthocresotinic acid with phenols with which the condensation cannot take place in para-position to the hydroXyl-group.

The new dyes are dark powders soluble in dilute caustic soda lye generally with a red color, dyeing wool from acid baths generally from red to violet shades, which can be chromed on the fiber.

In order to illustrate the new process more fully the following example is given, the parts being by weight :-12.2 parts of methylene-di-ortho-creso-tinic acid and 6 parts of para-cresol are stirred at from 20t5 C. together with 180 parts of a strong sulfuric acid and the necessary quantity of nitrosyl sulfuric acid until the quantity of the dyestuff produced does no longer increase and the evolution of nitrogen oxide ceases. The product of the reaction is poured on ice and the dyestuif is filtered off. It is a reddishbrown powder which dyes wool red which turn intense blue-violet on chroming.

Other oxidizing agents such as nitric acid, nitro compounds, concentrated or fuming sulfuric acid may be used. Methylene-di- Application fil ed April 2'7, 1910. Serial No. 557,950.

salicylic or methylene-di-Q L-diOXybenZoic acid, etc., or mixed methanes can be used instead of methylene-di-ortho-cresotinic acid and other of the above mentioned phenols may be employed, 6. g. parachlorophenol, 4.6 dibrom. 3. methylphenol para-cresotinic acid, para-chlorosalicylic acid, 2-naphthol- 3.6-disulfonic acid, 2-naphtholcarboxylic acids Q-naphthol 3 carboxy 6 sulfoacid, 2 naphthol 3 carboxy 8 sulfoacid etc.

The new dyestuffs can also be dyed on chromed wool or on wool together with chromium compounds.

I claim 1. The herein described new dyestuifs obtainablefrom methylene oXycarboXylic acids and phenols in which the para position to the hydroxyl group is substituted, which dyestufis are dark powders soluble in dilute caustic soda lye generally with a red color, dyeing wool from acid baths generally from red to violet shades, which can be chromed after dyeing, substantially as described.

2. The herein described new dyestuff 0btainable from methylene-di-ortho-cresotinic acid and para-cresol, which is a reddish brown powder soluble in caustic soda lye with a red color, dyeing wool red shades, which turn intense blue-violet on chron'iing, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

MAX VEILER.

litnesses OTTO Konic, VALTER VONNEGUT. 

